Toward a Treatment of Cancer: Design and In Vitro/In Vivo Evaluation of Uncharged Pyrazoline Derivatives as a Series of Novel SHP2 Inhibitors

Src homology 2 domain-containing protein tyrosine phosphatase 2 (SHP2) is a non-receptor protein tyrosine phosphatase (PTP) encoded by the PTPN11 gene, which is involved in the RAS/MAPK cell signaling transduction process. SHP2 has been shown to contribute to the progression of various cancers and is emerging as an important target for anti-tumor drug research. However, past efforts to develop SHP2 inhibitors into drugs have been unsuccessful owing to the positively charged nature of the active site pocket tending to bind negatively charged groups that are usually non-drug-like. Here, a series of uncharged pyrazoline derivatives were designed and developed as new SHP2 inhibitors using a structure-based strategy. Compound 4o, which exhibited the strongest SHP2 inhibitory activity, bound directly to the catalytic domain of SHP2 in a competitive manner through multiple hydrogen bonds. Compound 4o affected the RAS/MAPK signaling pathway by inhibiting SHP2, and subsequently induced apoptosis and growth inhibition of HCT116 cells in vitro and in vivo. Notably, the oral administration of compound 4o in large doses showed no obvious toxicity. In summary, our findings provide a basis for the further development of compound 4o as a safe, effective and anti-tumor SHP2 inhibitor.